GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Peyritschia pinetorum

HABIT Perennial; caespitose. Culms 35–70 cm long. Lateral branches lacking. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 1.5–3 mm long. Leaf-blades 1–2 mm wide. Leaf-blade surface scaberulous; glabrous, or puberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; dense; 8–20 cm long; 0.7–1.5 cm wide. Primary panicle branches appressed. Panicle axis scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 5.9–6.1 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose; with 1.5–2.2 mm long hairs. Floret callus pilose. Floret callus hairs 0.8–1.5 mm long.

GLUMES Glumes persistent; similar; reaching apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume elliptic; 5.9–7.1 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 5.9–7.1 mm long; 1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 4.9–6 mm long; membranous; keeled; 5 -veined. Lemma surface scaberulous; rough above. Lemma apex dentate; 4 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 7–12 mm long overall; with twisted column. Column of lemma awn 0.5 length of limb. Palea gaping; hyaline. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 2; 1.7–2.2 mm long.

FRUIT Caryopsis with adherent pericarp; 1.8 mm long. Hilum punctiform. Endosperm liquid.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Aveneae. Fl Meso-Am 1995.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.